Device for creating oscillations



Feb. 2 0, 1951 o. J. ALv REi 2,54

DEVICE FOR CREATING OYSCIILLATIONS Filed July 24, 1948' 3 Sheets-Sheet l IN V EN TOR.

0r4 W0 J AL MAKE Z W-WJ Feb. 20, 1951 o. J. ALVAREZ 2,542,271

DEVICE FOR CREATING OSCILLATIONS Fil'ed July 24, 1948 s Sheets-Sheet 2 INVENTOR. Oar/1W0 J 44 MAKfZ Feb. 20, 1951 o. J. ALVAREZ DEVICE FOR CREATING OSCILLATIONS 3 Sheets-Sheet 3 Filed July 24, 1948 .z R 2 mm X I Patented Feb. 20, 1951 DEVICE FOR CREATING OSCILLATIONS Octavio Jose Alvarez, New York, N. Y., assignor, by mesne assignments, of one-fourth to Maria De Reitzes-Marienwert, New York, N. Y.

Application July 24, 1948, Serial No. 40,506

17 Claims. 1

The present invention relates to electrical musical instruments, such as electrical pianos, and more particularly to devices for creating a longitudinally extended magnetic field and also to electrical vibration pick-up arrangements usable in electrical musical instruments and also in other fields.

It is an object of my present invention to produce on an electrical musical instrument a pianolike tone.

It is a further object of my present invention to provide a musical instrument adapted to produce piano-like tones without the use of strings and hammers.

It is a further object of my present invention to provide a piano-like instrument with means for producing piano-like tones which means are substantially less expensive and not so easily damageable as the strings and hammers of pianos of conventional type.

A still further object of my invention is to provide an instrument which produces mechanical oscillations which are not audible per se but are adapted to create electrical current oscillations.

Another object of my present invention consists in new means for transforming the above mentioned non-audible mechanical vibrations into electrical oscillations which are then transformed into oscillations of the membrane of a loud speaker or car phone.

With the above objects in view, a device for creating a longitudinally extended magnetic field usable in electrical musical instruments and other fields comprises in combinaton three longitudinal permanent magnetic members arranged parallel and spaced from each other in such a manner that the middle longitudinal magnetic member projects beyond the front end portions if the outer longitudinal magnetic members, and an electrically conductive member arranged between the outer longitudinal magnetic members contacting the same and the rear end portion of the middle longitudinal magnetic member in such a manner that the front end portions of the outer longitudinal magnetic members project beyond the electrically conductive member.

I have found it of advantage to use two outer longitudinal relatively strong permanent or elec tro-magnetic members and to make the middle magnetic member weaker, i. e. to use in the middle a weaker permanent or electro-magnetic member.

I have found that with an arrangement of the above type I am able to createas will be described farther below in detail-a longitudinally extended magnetic field projecting from the front end of the middle weaker magnetic member defined above.

If the above arrangement is used for creating the desired vibrations in an electrical sound reproducing instrument, I use as middle magnetic member a longitudinal permanent magnetic vibration reed.

The entire device for creating the desired magnetic vibrations comprises-if used in an electrical piano-a turnable holding arm, a magnetized freely vibratable steel reed secured to the turnable holding arm, two longitudinal permanent magnetic members secured also to the holding arm parallel to and spaced from the magnetized freely vibratable steel reed so that the magnetized freely vibratable steel reed projects beyond the front end portions of the longitudinal permanent magnetic members, pivoting means turnably supporting the turnable holding arm, and stop means arranged in the path of turning of the turnable holding arm.

In order to properly adjust the vibrations of the holding arm itself so as not to interfere to an unde ired degree with the vibrations of the reed, I provide adjusting means, e. g. an adjusting screw, freely turnably screwed into that end portion of the holding arm to which the reed is secured so as to enable varying of the length of the holding arm, enabling adjustment of the oscillations of this arm.

In accordance with a particularly preferred embodiment of my present invention, the entire arrangement includes an electrical vibra- Preferably, I employ as electrically conductive member a slightly magnetic member arranged between the outer longitudinal magnetic members contacting the same and the rear end portion of the middle longitudinal magnetic member in such a manner that the front end portions of the outer longitudinal magnetic members project beyond the slightly magnetic member.

tion pick-up arrangement comprising in combination two elongated stationary inductance coils forming a slot between themselves and Wound in such a manner as tocreate in a common electrical circuit oppositely directed electrical currents, a turnable holding member, a magnetized freely vibratable steel reed secured to the turnable holding arm, two longitudinal permanent magnetic members secured also to the holding arm parallel to and spaced from the magnetized freely vibratable steel reed so that the magnetized freely vibratable steel reed gated stationary inductance coils, and vibration creating position in which the longitudinally extended magnetic field created by the magnetized.

freely vibratable steel reed is projecting into the slot between the elongated stationary inductance coils, and stop means arranged in .thepathof turning of the turnable holding armso as to is in vibration creating position in which the longitudinally extended magnetic field created by the magnetized freely vibratable steel reed is projecting into the slot between the elongated stationary inductance coils.v

The novel features which I consider as characteristic for my invention are set forth in particu'- lar. in the appended claims. The invention itself,

however, both as to itsconstructon'and its:

method of operation; together with additional objects and advantages thereof, will. be best understood from the following description of specific embodiments when read in connection;

with the accompanying drawings, in which:

Fig. 1 is a schematic view of an arrangement for creating a longitudinally extended magnetic field;

Fig. 2 is a schematic View of a modification of the arrangement shown in Fig. 1;

Figs. 3 and 4 are still further modifications oi the device shown in Fig. 1';

Fig. 5 is a perspective View ofa detail of an electrical piano in accordance with my present invention in inoperative position, embodying the arrangement shown in Fig. 4; and

Fig. 6 is a perspective vview of a part .of .the electrical piano. shown in Fig. 5, in operative position.

In Fig. l, I have shown an arrangement which includes .three permanent magnets, namely,. a middle magnet Ill, and two outer magnets II and I2.of same po arity- These outer magnets. H

and '12 are arranged, as .clearlyshown, slightly,

incl ned towards the middle magnet I0.

I have found that in an arrangementaof this.

type the two outer magnets l I and.l2 to .a certain degree compress the .magnetic fieldv emanating. from theend 13 .of the middlemagnetllfl forme.

ing a somewhat longitudinally extended magnetic field. I4, as clearly shown inFig; l.

In .thearrangement. shown in Fig: 2,..the two outer .magnets 55 land [dare arranged parallel to the middle magnet. I'L. Also in an arrange-' ment of this type, a reatively longitudinallyexe. tended magnetic field l8is formed at the. end IQ of the permanent magnet H.

As shown in Fig. 2, the magnetic fieldsZEl and 2! formed at the upper ends. 22 and 23,.respec-- tively, of the outer magnets l5 and I6 are forced outward by the. middle magnet. IT. This is always the case if the middle magnet is stronger than the flanking magnets.

If, as shown in :Fig. 3,-Iarrange between the outer permanent. magnets 24 and 25 a member 26 of ferrous material, i. e. a material which is only slightly magnetic and cannot well retain magnetic fields 21 and. 28 emanating at theends 29 and 3B of thepermanent magnetism, the

magnets 24 and 25, respectively,-wi1l be attracted by the middle member 26 and a bunch-like magnetic field 3i will be formed at the upper end 32 of the member 26.

I have found that I can obtain best results, i. e. a longitudinally extended magnetic field, by arranging between the outer permanent magnets 33 and 34, as shown in Fig. 4, a block 35 of a ferrous material not adapted to serve as a permanent magnet, andto embed the middle permanent magnet 36 with one end 31 into the block 35. The result will be that the magnetic fields 3B and 39 emanating from the top ends 43 and i! of the permanent magnets 33 and 34, respectively, will be attracted by the iron block 35 as indicated by arrows 42, and enter the middle permanent engage the same when the turnable holding armr magnet 36. This, in turn, will increase the intensity of the magnetic field created by this middle permanent magnet, and, furthermore, will force part of the magnetic fields 38 and 39 to pass along opposite faces of the middle permanent magnet 35, creatinga longitudinally extended magnetic field 43 at the top, end 44 of the permanent magnet 36, as clearly shown in Fig. 4.

It should be noted that in the drawingl have not shown the flux lines but that the magnetic fields indicated in the drawings with reference numerals 14, I8, 21, 28, 3|, 38, 39, and ii'l'are representations of the positionoi iron dust fol.- lowing the fldx lines.

I 'wish to note thatth'e middle magnets describedabove might have any desired shape.v It is only important that they are longitudinal.

Arrangements of. this type might be used for.

various purposes. However, the preferred field .of. use. of such arrangements are. electrical acoustical" instruments in which the middle permanent magnet is madeof steel and is bandshaped soas to be adapted .tooscillate .and serve as an oscillation creating reed.

above in an electrical piano isshown in Figs. v5 and.6.-. As shown in these.figures,.the piano includes several piano keys, indicated by the reference numeral 45; each .of these piano keys is turnably pivoted at 46 to the body of the piano,-

responding to the middle permanent magnet 36.

of Fig. vLandon opposite .sidesof .the..b.lock 5|,

I .mount .thepermanent magnetic members 53,

and .54 corresponding to the outer permanent magnets 53.and 34 of Fig. l.

By this arrangement, itis possible to .createat the .free end-55of reed .52 a longitudinally eX-- tended magnetic field .56.

It is evident that if key 45 is depressed in direction of arrow 49 and abruptlyabuts against the .stop member 41,- the reed 52 will be forced to oscillate in direction of arrow 51, as indicated in Fig.6. Of course, oscillation of the reed will also cause oscillation of the magnetic field 55.

In order to avoid undesired interferencebetween oscillation of the .key 45 and reed 52 after striking the key, I provide at the front end of the key a screw 58 which is adjustable relative to the key; by turning of this-screw, it is possible to adjust the frequency. 01' oscillations of. the key 45 An application of the arrangements described and thereby avoid interference of such oscillations with the oscillations of reed 52.

In order to transform the oscillations of the longitudinally extended magnetic field 56 into electrical current variations which, in turn, might be transformed into audible signals, I provide in accordance with my present invention two parallelly arranged stationary inductance coils 59 and 60, forming between themselves the slot Bl.

I wish to stress that the stop member 4'! has to be arranged in such a manner that the longitudinally extended magnetic field 56 enters the slot 6! when the key 45 is in the position shown in Fig. 6 after striking of the same.

In this position, the magnetic field 55 oscillates within the slot 6|, i. e. between the two induct ance coils 59 and 60.

I wish to note that in accordance with my present invention the windings G4 and 65 of the stationary inductance coils 59 and 60 are arranged so as to create in a common electrical circuit oppositely directed electrical current. Thus, if the two coils are at the same moment equally influenced by an outer electrical source located paced from the two inductance coils, the same will be equally influenced and the electrical currents created in the two coils will be equal and oppositely directed and thus practically cancel and eliminate each other.

In this manner, it is possible to avoid any outer undesired electric and magnetic influences upon the pick-up device.

Contrary thereto, the oscillating magnetic field 55 oscillates between the two inductance coils 59 and 66 and thereby differently influences the same at the same moment. Thus, the electrical currents created by these oscillations of the magnetic field 55 do not cancel each other but are combined so as to create after amplification by the amplifier 62 audible signals transmitted by the loud speaker 63.

I wish to stress that I have found that it is possible to simultaneously pick up a plurality of oscillations created by a plurality of piano keys with the same two stationary inductance coils to create in said inductance coils a plurality of independent currents corresponding each to one of the oscillations, and to reproduce these currents in such a manner that the audible signals corresponding to each of the oscillations are independent and clearly distinguishable from each other.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of acoustical instruments, differing from the types described above.

While I have illustrated and described the invention as embodied in electrical pianos, I do not intend to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of my invention.

Without further analysis, the foregoing will so fully reveal the gist of my invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention, and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What I claim as new and desire to secure by Letters Patent is:

1. For use in an electrical musical instrument a devic for creating a vibrating longitudinally extended magnetic field comprising in combination three longitudinal permanent magnetic members, namely two outer longitudinal permanent magnetic members and a middle longitudinal permanent magnetic vibratable reed arranged parallel and spaced from each other in such a manner that said middle longitudinal permanent magnetic vibratable reed projects beyond the front end portions of said outer longitudinal permanent magnetic members.

2. For use in an electrical musical instrument a device for creating a vibrating longitudinally extended magnetic field comprising in combination three longitudinal permanent magnetic members, namely two outer longitudinal permanent magnetic members and a middle longitudinal permanent magnetic vibratable reed arranged parallel and spaced from each other in such a manner that said middle longitudinal permanent magnetic vibratable reed projects beyond the front end portions of said outer longitudinal permanent magnetic members; and a slightly magnetic member arranged between said outer longitudinal permanent magnetic members in such a manner that said front end portions of said outer longitudinal permanent magnetic members project beyond said slightly magnetic member.

3. For use in an electrical musical instrument a device for creating a vibrating longitudinally extended magnetic field comprising in combination thre longitudinal permanent magnetic members, namely two outer longitudinal permanent magnetic members and a middle longitudinal permanent magnetic vibratable reed arranged parallel and spaced from each other in such a manner that said middle longitudinal permanent magnetic vibratable reed projects beyond the front end portions of said outer longitudinal permanent magnetic members; and a slightly magnetic member arranged between said outer longitudinal permanent magnetic members contacting the same and said middle longitudinal permanent magnetic vibratable reed in such a manner that said front end portions of said outer longitudinal permanent magnetic members project beyond said slightly magnetic member.

4. For use in an electrical musical instrument a device for creatin a vibrating longitudinally extended magnetic field comprising in combina tion three longitudinal permanent magnetic members, namely two outer longitudinal strong permanent magnetic members and a middle longitudinal weaker permanent magnetic vibratable reed arranged parallel and spaced from each other in such a manner that said middle longitudinal weaker permanent magnetic vibratable reed projects beyond the front end portions of said outer longitudinal strong permanent magnetic members.

5. For use in an electrical musical instrument a device for creating a vibrating longitudinally extended magnetic field comprising in combination three longitudinal permanent magnetic members, namely two outer longitudinal strong permanent magnetic members and a middle longitudinal weaker permanent magnetic vibratable reed arranged parallel and spaced from each other in such a manner that said middle longitudinal weaker permanent magnetic vibratable reed projects beyond the front end portions of said outer longitudinal strong permanent magnetic members; and a slightly magnetic member arrangedbetween said outerlongitudisaid outer longitudinal strong permanent magnetic members project beyond said slightly magnetic member.

6. For use in an electrical musical instrument a device for creating a vibrating longitudinally extended magnetic fieldcomprising in combina tion three longitudinal permanent magnetic members, namely two outer longitudinal strong permanent magnetic members and a middle longitudinal weaker permanent magnetic vibratable reed arranged parallel and spaced from each other in such a manner that said middle longitudinal weaker permanent magnetic vibratable reed projects beyond the front end portions of said outer longitudinal strong-perma nent magnetic members; and a slightly magnetic member arranged between said outer longitudinal strong permanent magnetic members contacting the same and said middle longitudinal weaker permanent magnetic vibratable reed in such a manner that said front end portions of said outer longitudinal strong permanent magnetic members project beyond said slight magnetic member.

7. For use in an electrical piano a device for a vibrating longitudinally extended creating magnetic field comprising in combination a turnable holding arm; a magnetized freely vibratable steel reed secured to one end of said turnable holding arm; two longitudinal permanent magnetic members secured also to said holding arm parallel to and spaced from said magnetized freely vibratable steel 'reed so that said magnetized freely vibratable steel reed projects beyond the front end portions of said longitudinal permanent magnetic members; pivoting means turnably supportin said turnable holding arm; and stop means arranged in the path of turning of said turnable holding arm.

8. For use in an electrical piano a device for creating a vibrating longitudinally extended magnetic field comprising in combination a turnable holding arm; a slightly magnetic block secured to one end of said turnable holding arm; a magnetized freely vibratable steel reed secured to said slightly magnetic block extending in direction of said holding arm; two longitudinal permanent magnetic members secured also to said slightly magnetic block parallel to and spaced from said magnetized freely vibratable steel reed so that said magnetized freely vibrat: l

beyond said slightly magnetic block; two longitu- V70 tosaid slightly magnetic block parallel to and dinal permanent magnetic members secured also spaced from said magnetized freely vibratable s' eel reed projecting slightly in the direction of said holding arm beyond said slightly magnetic block; pivoting means turnably.supportingsaid,

turnable holding arm; and stop means arranged, in the path of turning of said turnable holding arm.

10. For use in an electrical piano a device for creating a vibrating longitudinally extended, magnetic vfield comprising in combination a turnable holding arm; a magnetized freely vibratable steel reed secured to one end of said turnable holding arm; two longitudinal permanent magnetic m-mbers secured also to said holding arm parallel to and spacedfrom said magnetized freely vibratable steel reed so that said magnetized freel vibratable steel reed projects beyond the front end portions of said longitudinal permanent magnstic members; pivoting means turnably supporting said turnable holding arm; stop means arranged in the path of turning of said turnable holding arm; and adjusting means secured to said holding arm for varying the length of the same.

11. For use in an electrical piano a device for creating a vibrating longitudinally extended magnetic field comprising in combination a turnable holding arm; a slightly magnetic block secured to one end of said turnable holding arm;

able holding arm at one end thereof for varying the; length of saidholding arm,

12. For use in an electrical piano a device for creating I; a vibrating longitudinally extended magnetic field comprising in combination a turnable holding arm; a slightly magnetic block secured to one endjof said turnable holding arm; a magnetized freely vibratable steel reed secured to said slightly magnetic block projecting a substantial distance in direction of said holding arm beyond said slightly magnetic block; two longitu dinal permanent magn-tic members secured also to said slightly magnetic block parallel to and spaced from said magnetized freely vibratable steel reed projecting slightly in the direction of said holding arm beyond said slightly magnetic block; pivoting means turnably supporting said turnable holding arm; stop means arranged in the path of turningof said turnable holding arm;

and an adjusting screw freely turnably screwed into thatend portion of said holding arm to which said slightly magnetic block is secured so as to enable varying of the length of said holding arm.

l3.- In an electrical piano in combination an electrical vibration pick-up arrangJnent; a turnable holding arm; a magnetized freely vibratable i steel reed secured to one end of said turnable holding arm; two longitudinal permanent magneticmmibers secured also to said holding arm parallel to and spaced from said magnetized freely vibratable steel reed so that said magnetized freely vibratable steel reed projects beyond the front end portions of said longitudinal permanent magnetic members; pivoting means turnably supporting said turnableholding arm in such a manner that said magnetized freely vibratable steel reed secured to said turnable holding arm is adapted to move in the pickup sphere of said electrical vibration pick-up arrangement; and stop means arranged in the path of turning of said turnable holding arm so as to engage the same when said magnetized freely vibratable steel reed secured to said turnable holding arm is located near said electrical vibration pick-up arrangement in the pickup sphere of the same.

14. In an electrical piano in combination two elongated stationary inductance coils forming a slot between themselves and wound in such a manner as to create in a commonelectrical circuit oppositely directed electrical currents; a turnable holding member; a magnetized freely vibratable steel reed secured to one end of said turnable holding arm; two longitudinal permanent magnetic members secured also to said holding arm parallel to and spaced from said magnetized freely vibratable steel reed so that said magnetized freely vibratable steel reed projects beyond the front end portions of said longitudinal permanent magnetic members; pivoting means turnably supporting said turnable holding arm in such a manner that the same is movable between inoperative position in which the longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is not projecting into said slot between said elongated stationary inductance coils and vibration creating position in which said longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is projecting into said slot'between said elongated stationary inductance coils; and stop means arranged in the path of turning of said turnable holding arm so as to engage the same when said turnable holding arm is in vibration creating position in which said longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is projecting into said slot between said elongated stationary inductance coils.

15(In an electrical piano in combination two elongated stationary inductance coils forming a slot between themselves and wound in such a manner as to create in a common electrical circuit oppositely directed electrical currents; a turnable holding member; a slightly magnetic block secured to one end of said turnable holding arm; a magnetized freely vibratable steel reed secured to said slightly magnetic block projecting a substantial distance in direction of said holding arm beyond said slightly magnetic block; two longitudinal permanent magnetic members secured also to said slightly magnetic block parallel to and spaced from said magnetized freely vibratable steel reed projecting slightly in the direction of said holding arm beyond said slightly magnetic block; pivoting means turnably supporting said turnable holding arm in such a manner that the same is movable between inoperative position in which the longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is not projecting into said slot between said elongated stationary inductance coils and vibration creating position in which said longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is projecting into said slot between said elongated stationary inductance coils; and stop means arranged in the path of turning of said turnable holding arm so as to engage the same when said turnable holding 10 arm is in vibration creating position in which said longitudinally extended magnetic field created bysaid magnetized freely vibratable steel reed is projecting into said slot between said elongated stationary inductance coils.

16. In an electrical piano in combination two elongated stationary inductance coils forming a slot between themselves and wound in such a manner as to create in a common electrical circuit oppositely directed electrical currents; a turnable holding member; a slightly magnetic block secured to one end of said turnable holding arm; a magnetized freely vibratable steel reed secured to said slightly magnetic block projecting a substantial distance in direction of said holding arm beyond said slightly magnetic block; two longitudinal permanent magnetic members secured also to said slightly magnetic block parallel to and spaced from said magnetized freely vibratable steel reed projecting slightly in the direction of said holding arm beyond said slightly magnetic block; an ad usting screw freely turnably screwed into that end portion of said holding arm to which said slightly magnetic block is secured so as to enable varying of the length of said holding arm; pivoting means turnably supporting said turnable holding arm in such a manner that the same is movable between inoperative position in which the longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is not projecting into said slot between said elongated stationary inductance coils and vibration creating position in which said longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is projecting into said slot between said elongated stationary inductance coils; and stop means arranged in the path of turning of said turnable holding arm so as to engage the same when said turnable holding arm is in vibration creating position in which said longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is projecting into said slot between said elongated stationary inductance coils.

17. In an electrical piano in combination two elongated stationary inductance coils forming a slot between themselves and wound in such a manner as to create in a common electrical circuite oppositely directed electrical currents; a turnableholding member; a magnetized freely vibratable steel reed secured to one end of said turnable holding member; pivoting means turnably supporting said turnable holding member in such a manner that the same is movable between inoperative position in which the longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is not projecting into said slot between said elongated stationary inductance coils and vibration creating position in which said longitudinally extended magnetic field created by said magnetized freely vibratable steel reed is projecting into said slot between said elongated stationary inductance coils; and stop means arranged in the path of turning of said turnable holding member so as to engage the same when said turnable holding member is in vibration creating position in which said longitudinally extended magnetic field created by said magnetized freely vibratable reed is projecting into said slot between said elongated stationary inductance coils.

OCTAVIO JOSE ALVABEZ.

(References on following page) REFERENCES EI T ED .The following references are'of "rec'urd inthe file 61 this patgentz Number UNITED STATES PATENTS 5 Name Date Thomas May 12, 1931 Simms et a1. May 19, 1931 Loar July '6, 1937 Sinnett et a1. Jan. 11, 1938 10 Number I 

